Contiguous capillary electrospray sources and analytical devices

Abstract

Contiguous capillaries useful for separating and electrospraying a fluid comprising analyte and electrolyte are provided. The contiguous capillaries have spray tips at one end of the capillaries and electrically conductive portions in proximity to the spray tips. Methods for making the contiguous capillaries and their use as electrospray sources are also disclosed. Apparatus and methods for conveying analyte ions from the capillaries into analytical instruments, such as a mass spectrometer, are also disclosed. The disclosed contiguous capillaries may be used to carryout electrophoresis separation and electrospray ionization of analytes. Methods for obtaining the mass spectra of macromolecular analytes at concentrations lower than previously possibly are provided using the apparatus and procedures described herein.

Description

CROSS REFERENCE TO RELATED APPLICATIONS [0001] This application claims benefit of U.S. Provisional Application Ser. No. 60 / 420,003, filed Oct. 21, 2002, incorporated by reference herein in its entirety.GOVERNMENT RIGHTS [0002] The work leading to the disclosed inventions was finded in whole or in part with Federal funds from the National Cancer Institute, National Institutes of Health, under Contract No. NO1-CO-12400. Accordingly, the U.S. Government has rights in these inventions.FIELD OF THE INVENTION [0003] The present inventions are related to the field of molecular analysis of fluids comprising analyte and electrolyte using capillaries. Related are inventions for devices and methods for electrospraying analyte ions from capillaries into analytical instruments, such as a mass spectrometer. The capillaries may be used in the electrophoresis separation of, and in the electrospraying of analytes. BACKGROUND OF TH INVENTION [0004] Mass spectrometry (MS) is arguably among the most us...

AI Technical Summary

Benefits of technology

[0020] In another aspect of the present invention, there are provided methods of obtaining the mass spectra of analyte molecules. In these methods, the mass spectra are obtained by providing a fluid comprising analyte and electrolyte, providing one of the contiguous capillaries of an aspect of the present invention described herein, transporting the fluid through the contiguous capillary, providing an electrode exterior to the electrically conductive port

Problems solved by technology

The limits of these common detection techniques are particularly evident in the identification and analysis of macromolecules, such as peptides and proteins.

Coaxial sheath flow is the basis of most commercial instruments, though it suffers in sensitivity.

The low sensitivity of a coaxial sheath flow CE design arises largely from the relatively high sheath flow compared to the flow from the CE capillary, resulting in not only a large dilution of the eluting analytes, but also in hindered desorption of ions due to the non-optimal electrospray that results at such high flow rates.

Coupling CE online with MS through a liquid junction arrangement requires tedious capillary alignment and end-to-end butting of the separation capillary and the spray tip.

Unfortunately, even under the best conditions, sensitivity is compromised by loss and sp

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